The 2016 Stereo Room reverb plug-in from Eventide is based off the legendary SP2016. This multi-effect unit has been revered by industry legends such as Dave Pensado and George Massenburg.

The sp2016 was designed starting in 1978 or 79. When it first shipped in 1981 it had a small number of effects including Room and Plate reverbs. Stereo Room was developed a little later. New effects were created by Eventide and a start up company called First Order Effects for several years up until 1986. These effects included some first ever effects like Shimmer, Band Delays, Timescramble as well as vocoders, etc.

Eventide used the term "plug-in" as purely descriptive because you added effects by plugging in a ROM into a ZIF socket (Zero Insertion Force). The unit shipped with several empty sockets and users were sent new effects as they became available. They used the term plug-in from the beginning of the project in 1978 and, as far as they know, this predates any other use of the term. The first Macs and PCs appeared around then but there was no notion of plugging in new software. Back then it was floppy disks.

In these videos you can see an overview of the controls as well as hear audio examples on different instruments.